Compare Pointers for Equality (CMPPTRE)

Operand 1: Pointer data object

Operand 2: Pointer data object

Operand 3 [4]:

• Branch Form-Instruction number, relative instruction number, branch point, or instruction pointer.

• Indicator Form-Numeric variable scalar or character variable scalar.

Description:   The pointer specified by operand 1 is compared with the pointer specified by operand 2 to determine if both operands are of the same type and contain equal values. Based on the comparison, the resulting condition is used with the extender to transfer control (branch form) or to assign a value to each of the indicator operands (indicator form).

Pointers may be specified for operands 1 and 2 in any combination. An equal condition occurs if the pointers are of the same type and contain the same value, or if neither pointer has been set. If one pointer is set and the other is not, a not equal condition occurs.

System pointers and data pointers are not resolved by this instruction. The comparison result is undefined when an unresolved pointer is supplied for one or both operands.

Note that any authorities stored in a resolved system pointer are part of the pointer. Thus system pointers pointing to the same object, but with different levels of authority, will compare as not equal.

Since any pointer type may be specified for this instruction, the pointer type invalid  (hex 2402) exception is not signaled except for pointers used as a base for the operands. Similarly, since the instruction accepts unset pointers, the pointer does not exist  (hex 2401) exception is not signaled except for pointers used as a base for the operands.

While it is possible for two synchronization pointers to compare as equal, the item referenced by the pointer may not be usable from both pointer locations. A copied synchronization pointer is not useful, because a synchronization pointer is defined to reside at only a single location in memory.

Resultant Conditions:  

• Equal

• Not equal

Authorization Required

• None

Lock Enforcement

• None

Exceptions

06 Addressing

• 0601 Space Addressing Violation
• 0602 Boundary Alignment
• 0603 Range

08 Argument/Parameter

• 0801 Parameter Reference Violation

0A Authorization

• 0A01 Unauthorized for Operation

10 Damage Encountered

• 1004 System Object Damage State
• 1005 Authority Verification Terminated Due to Damaged Object
• 1044 Partial System Object Damage

1A Lock State

• 1A01 Invalid Lock State

1C Machine-Dependent

• 1C03 Machine Storage Limit Exceeded

20 Machine Support

• 2002 Machine Check
• 2003 Function Check

22 Object Access

• 2201 Object Not Found
• 2202 Object Destroyed
• 2203 Object Suspended
• 2207 Authority Verification Terminated Due to Destroyed Object
• 2208 Object Compressed
• 220B Object Not Available

24 Pointer Specification

• 2401 Pointer Does Not Exist
• 2402 Pointer Type Invalid

2E Resource Control Limit

• 2E01 User Profile Storage Limit Exceeded

36 Space Management

• 3601 Space Extension/Truncation

44 Protection Violation

• 4401 Object Domain or Hardware Storage Protection Violation